The Training Core within the Boston University Superfund Basic Research Program (BU SBRP) will work in the settings of two primary existing training programs, the first an NICHD Training Program in "Endocrine Mechanisms in Vertebrate Reproduction," within the Department of Biology at Boston University, the second, large NSF- sponsored Integrated Graduate Research and Training (IGERT) program at Bioinformatics, a joint effort based in the Departments of Biomedical Engineering, Biology, Mathematics, Computer Science and Chemistry. Several other training programs within the Department of Biology will also serve as resources. The Core explicitly responds to the need to provide students of the biomedical sciences opportunities to learn about non-biomedical areas of study, and vice-versa. Five projects (compromising three biomedical and two non-biomedical projects) have significant requirements for molecular modeling of enzyme and steroid receptor sites for xenobiotics. Thus there is a major need for integrations of computational components into the training of the predoctoral students cohort within the BU SBRP and in the biological and environmental health fields in general. Candidates will be selected from successful recruits to the existing highly competitive training programs. Each student will have dual mentors, one in the engineering (computational) sciences, one in experimental (laboratory) sciences. There will be required interdisciplinary coursework and seminars, and required participation in the Outreach Core for the community.